title: Relationship between MTNR1B (melatonin receptor 1B gene) polymorphism rs10830963 and glucose levels in overweight children and adolescents.
abstract: OBJECTIVE
  The G-allele of the single nucleotide polymorphism (SNP) rs10830963 in MTNR1B (melatonin receptor 1B gene) is associated with type 2 diabetes mellitus and glucose levels in adults. The aim of this study was to analyze whether there is an allele-dosage effect on glucose metabolism in overweight children and to explore if changes in glucose metabolism in a lifestyle intervention do also depend on genotype.
  
  
  METHODS
  We genotyped rs10830963 in 1118 overweight children and adolescents [mean age 10.7 yr, mean body mass index (BMI) 27.8 kg/m2]; 340 of these individuals completed a 1-yr lifestyle intervention (mean age 10.7 yr, mean BMI 27.9 kg/m2). The degree of overweight [BMI-SDS (standard deviation score)], fasting insulin, glucose, homeostasis model assessment for insulin resistance (HOMA-IR), and quantitative insulin sensitivity check index (QUICKI) were measured before and after intervention.
  
  
  RESULTS
  We showed a significant relationship between rs10830963 and basal glucose levels [β:1.101, 95% confidence interval (CI) 0.316-1.886 mg/dL per risk allele; p = 0.006] by linear regression adjusted for age, age(2), and sex. There was no effect of the allele on insulin or indices of insulin resistance or sensitivity. After the 1-yr lifestyle intervention, we observed a significant reduction of BMI-SDS as well as an improvement of HOMA-IR and QUICKI, but no evidence for an association between rs10830963 genotype and changes of glucose levels.
  
  
  CONCLUSIONS
  The G-allele of rs10830693 in the MTNR1B gene was significantly related to glucose levels, while an impact of this genetic variant on the changes in glucose metabolism in children participating in a lifestyle intervention was not observable.
authors.affiliation: Department of Pediatric Endocrinology, Diabetes and Nutrition Medicine, Vestische Hospital for Children and Adolescents Datteln, University of Witten/Herdecke, Germany. T.Reinehr@kinderklinik-datteln.de
authors.forename: Thomas
authors.initials: T
authors.lastname: Reinehr
authors.forename: André
authors.initials: A
authors.lastname: Scherag
authors.forename: Hai-Jun
authors.initials: HJ
authors.lastname: Wang
authors.forename: Christian L
authors.initials: CL
authors.lastname: Roth
authors.forename: Michaela
authors.initials: M
authors.lastname: Kleber
authors.forename: Susann
authors.initials: S
authors.lastname: Scherag
authors.forename: Tanja
authors.initials: T
authors.lastname: Boes
authors.forename: Carla
authors.initials: C
authors.lastname: Vogel
authors.forename: Johannes
authors.initials: J
authors.lastname: Hebebrand
authors.forename: Anke
authors.initials: A
authors.lastname: Hinney
mesh_terms: D000293:Adolescent; D001786:Blood Glucose / Q000378:metabolism; D002648:Child; D005260:Female; D005858:Germany; D006801:Humans; D007333:Insulin Resistance / Q000235:genetics; D008019:Life Style; D008137:Longitudinal Studies; D008297:Male; D050177:Overweight / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide; D044123:Receptor, Melatonin, MT2 / Q000235:genetics*
chemical_list: D001786:Blood Glucose; D044123:Receptor, Melatonin, MT2